As a distributed company, time zones are inevitably a source of confusion and frustration, especially when working and scheduling with colleagues in another part of the world.
To minimize the pain, we only use UTC when internally communicating. Whether scheduling meetings, organizing a coffee break, or letting someone know what time you'll be starting that day, you should do so in UTC, regardless of whether the person you're communicating with is in the same timezone as you are.
Using only UTC means that you only ever need to know your current UTC offset, not those of your colleagues, and reduces the amount of change that happens throughout the year due to different daylight savings schedules in different regions.
More info on UTC can be found here.